ES2260604T3 - PLASTIC COVER AND METHOD TO MANUFACTURE THE SAME. - Google Patents

Abstract

The invention concerns a plastic cap (1) and a container (4) using same. The plastic cap (1) comprises an oxygen-tight liner (8) to be joined to an opening end surface (6) of a spout (5) on the container (4). The cap (1) has a circumferential skirt (2) with an internal annular bead (3) adapted for snap connection with a corresponding annular groove (7) in the spout (5). The liner (8) has on the side facing the cap (1) a first plastic layer (81), which is arranged to be permanently joined, when injection-molding the cap (1), to the plastic material of the cap (1), and on the side facing the container (4) a second plastic layer (82), which is arranged to be temporarily hermetically sealed to said opening end surface (6). On the end facing the container (4), the skirt (2) has a radial projection (10) which serves as a thumb grip and which when opening the container (4) allows the cap (1) to be bent away from said opening end surface (6) so that the temporary, hermetic seal between the second plastic layer (82) of the liner (8) and the opening end surface (6) of the spout (5) is gradually broken. The liner (8) comprises an intermediate layer (83) which is made of metal material enabling induction welding of the cap (1) to the opening end surface (6) of the container (4).

Description

Plastic lid and method to manufacture the same.

Field of the invention

The present invention relates to a cover of plastic for a container, whose lid, for sealing impervious to container oxygen, comprises an oxygen impermeable liner a be attached to an extreme opening surface of a mouth of discharge (which in the following of this memory and of the claims we will call simply as mouth) in the container and, for fixing to the mouth has a skirt circumferential, which is arranged to surround the mouth and It has an internal annular cord adapted for adjustment connection fast with a corresponding annular stretch mark in the mouth, having the lining an intermediate layer impermeable to oxygen, whose side that looks towards the lid is coated with a first layer of plastic arranged to be permanently attached to the lid and whose side that look towards the container is coated with a second layer of plastic arranged to be hermetically sealed, temporarily, to said opening end surface, and the lining and lid being joined together so that when the cover is removed the liner Accompany the lid. The invention also relates to a method for manufacturing such a cover by means of a mold, which comprises a first part of mold having a cavity and a second part of mold that has a core.

Background of the invention

A cover of the type defined by way of introduction is known from the specification of the patent GB-A-1,571,938. More specifically, this document describes a temporary hermetic seal between an extreme opening surface in the mouth of a container and an oxygen impermeable forum, which is mounted on the lid, and the permanent union of the forum and the lid, preferably by induction heating of the plastic layers on both sides of the liner after mounting the lid on the container
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A first drawback of this method is that of that a fitting is required to mount the cover on the cover in precise position of the cover before inserting the lining, that is, that a special mounting unit is required, which rotates first the cover to take it to its correct position and then insert the cover. A second drawback is that, regardless of where that assembly unit is located on the production line, there is still the risk of a lining falling out of the cover of again, making it impossible to obtain a tight seal between a container and the defective lid.

In the document DE-A1-196 21 617 has described a manufacturing method, other than the one stated in the document GB-A-1,571,938. According to the descriptive report of that patent, which refers to a cover threaded, a liner is inserted into a mold, in which the lining in a way that is not described in greater detail. Later injects a plastic into the mold, thereby making it a layer of special separation on one side of the lining is joined by fusion with the plastic material of the lid. Finally, the lid is mounted on the mouth of a container, where the container is glued by means of a tail thread applied to the extreme surface of the mouth. When remove the lid of the container, the lining remains in the container, since the adhesive force of the tail thread exceeds the force Adhesive layer separated from the liner.

A first drawback of the solution of according to document DE-A1-196 21 617 is that, regardless of the type of container, it is it is necessary to apply the tail thread in relation to the assembly of the lid on the container, and that that application of the tail thread it constitutes an extra operation, which must be carried out before of the actual cover assembly. A second drawback is that the lining, which remains after the cover is removed, prevents rapid opening of the container. In addition, the lid that remains makes it more difficult, particularly for people with incapacitation, open the container. In addition, it is declared in the document DE-A1-196 21 617 that the liner is inserted into the mold when the lid is manufactured, but it is not It says where it should be placed in the mold.

In these circumstances, it is reasonable to assume that the liner is supposed to be placed in the mold in the same way that is said in the patent specification above known US-A-4,774,134. Agree with this document, a liner that has a first flat side of a fusible plastic material is placed with a second flat side opposite on the core of a mold, after which the mold and plastic is injected around the core and the liner placed on it. This makes the plastic and the material plastic lining join together by fusion, thus being united permanently.

A first drawback of the solution of agreement with the document US-A-4,774,134 is the one that has been added an extra operation after the lid was manufactured, in whose operation is injected into the lid an annular gasket in shape of a string of sealing material. A second inconvenience is that the placement in position of the lining on the core of the mold slows the core cooling process when it opens the mold, which can result in a cycle time considerably longer. The vacuum channels to retain the lining over the core also make it more difficult to provide coolant channels in the core, whose channels could contribute to a reduction in core temperature and, by consequently, to a reduction of the cycle time.

Another cover in the form of a threaded cover, which it has certain properties common to those of the lid defined by way of of introduction, it is already known from the descriptive memory of the US-A-5,927,532. More in In particular, a cover is described in that specification resistant to its opening by children, which in one embodiment has a insert with a thin lining, which can be welded to an extreme surface of the mouth to obtain impermeability to oxygen. When the container is opened, the welded joint is broken, raising the insert at the same time as the lid, as the insert is pulled by a cord circumferential on the lid. It is thus possible to remove the lid and break the oxygen-impermeable seal with a single movement of grab

A first drawback of this cover of the prior art is that it is comparatively difficult to manufacture, since it consists of several parts that have to be assembled in a separate assembly operation. A second drawback is the that the lifting movement to break the seal must be made by pulling the container and the lid for it separate them, which requires a relatively large force and gives frequently resulting in an abrupt opening movement, which It may cause spillage of part of the contents of the container. Another drawback is that the division of the operation of opening in two separate steps makes it difficult to know if it has Broken the seal, or not.

Object of the invention

In the light of the foregoing, the Object of the present invention is to provide a plastic cap, the which is considerably easier to manufacture and open than of prior art solutions. Another object of the invention is provide an easy and effective way to manufacture that lid.

Summary of the invention

The first object is achieved according to the invention by means of a cover which is of the type defined by way of introduction and characterized in that said plastic lid is ready to be permanently attached, when molded by injection the lid, to the plastic material of the lid, and because the skirt at the end facing the container has a radial projection that serves as a grip point for the thumb and the which, when the container is opened, allows the lid to be folded outwardly from said extreme opening surface, so that the temporary hermetic seal is broken gradually between the second plastic layer of the liner and the extreme opening surface of the mouth.

By joining the liner directly to the cover in relationship with injection molding, instead of placing the liner on the finished cap after the injection mold, you get a much simpler and cheaper solution than the document GB-A-1,571,938. In addition, this solution offers the advantage that the liner cannot fall out of the lid, since it is already permanently attached to the plastic material of the cover in injection molding. In addition, the radial projection that it serves as a grip for the thumb is one more solution user friendly than the fin to pull, okay with the descriptive memory of the British patent, since the fin to pull is intended to be grabbed with the thumbs and index, for which strong fingers are required and the use of both hands, one hand to hold the container and the other for the grip with the thumb and index finger. As for the thumb grip used with the lid according to the invention, this can be obtained with only one hand, holding the user by hand the container and making an opening movement with the thumb radial projection in the axial direction of the container. This axially directed opening movement can also be performed, of course, in some other suitable way, for example, by the application of radial projection to the table's bode and moving the container down in relation to that edge, and that movement it is still easier to execute, since the lid bends towards outside, when the container is opened, from the extreme surface of opening of the container, so that the seal is gradually broken airtight between the second plastic layer of the liner and the Extreme opening surface of the mouth. This feature is not says they own it none in any of the descriptive reports of the aforementioned patents, in particular not in relation to the cover according to the document GB-A-1,571,938, in which there are arranged radial reinforcement tabs to prevent double.

Preferably, said radial projection is a tab that extends along the entire circumference of the top. The advantage of this solution is that a designed lid of this way is easy to open, regardless of the position of the container, that is, that the solution is particularly suitable for, for example, beverage containers that must be open with a rapid movement with the thumb.

It is assumed that the skirt may have a hoop that evidences that a fraud has been committed, in the end that look towards the vessel, whose hoop is willing to cooperate with corresponding retention means in the mouth and so that break, separating from the lid, when the lid is removed from the mouth. It will be understood that such a hoop to evidence that a fraud can be designed in a number of appropriate ways and that the corresponding means of retention in the mouth can be, by example, in the case of a quick-fit cover, a stretch mark circumferential.

According to a preferred embodiment, the middle layer of the lining is made of a metallic material, of so that the liner is weldable by induction welding to the extreme opening surface of the container. Metallic material it is preferably a thin sheet of aluminum, but it is also they can use other metal materials suitable for that purpose. The advantage of induction welding is that heat due to the metallic material, automatically concentrates in the desired place, that is, in the boundary layer between the liner and the surface Extreme opening of the mouth.

According to an alternative embodiment, the Second layer of plastic liner is a layer that is applicable to the Extreme opening surface of the container by means of adhesive. The advantage of this solution is that the lid according to the invention will be able to seal in an oxygen impermeable manner too containers that are not suitable for induction welding or Ultrasonic

According to another embodiment, the second layer Plastic lining is a layer that is weldable to the surface Extreme opening of the container by ultrasonic welding. This realization can be useful in particular if for reasons environmental use it was not desirable to use any metallic material and if for the same reasons it is not desirable to use adhesive for bonding from the lining on the lid to the extreme opening surface of the mouth. However, ultrasonic welding requires placement in relatively precise position of the container in relation to the welding head, and is therefore more difficult to use than the induction welding.

The second object is achieved, according to the invention, by a method of the type defined in the part of introduction, whose method comprises the steps of inserting a liner, the mold being open, in the cavity of the first part of mold, where it is applied to a first flat side of a wall of the mold, close the mold by means of the second mold part, whose nucleus is then inserted into the cavity of the first part of mold, inject plastic through at least one opening in said wall of the mold, on the first flat side of the liner so that the plastic flow on said flat side, press on the second opposite flat side of the liner against said core, and fill a cavity that remains between the mold parts, and open the mold and remove the finished cover with the lining incorporated in it.

This method is considerably easier to put into practice that prior art methods before mentioned, and due to the application of the first flat side of the lining to a mold wall of the first mold part, they are obviated effectively all the above limitations due to possible mold core heating. The application of the lining to the mold wall is preferably obtained by a pressure negative that is created in said at least one opening in said wall of the mold.

Brief description of the drawings

A more detailed description is given below. preferred embodiment of a lid and a preferred method for manufacture it, with reference to the schematic drawings that are accompany, in which:

Fig. 1 is a partially sectioned view transverse of a lid in the form of a quick-fit lid with a hoop to show that fraud has been committed;

Fig. 2 is a view of the adjustment cap fast when being removed from a container; Y

Figs. 3-5 illustrate different steps of manufacturing a lid in the form of a lid quick adjustment, without a ring that shows that a fraud.

Detailed description of the preferred embodiment and method to make the same

In Figs. 1 and 2 a preferred embodiment of a plastic lid1 according to the invention. As is evident, the plastic cover 1 has the form of a quick-fit cap, which has a circumferential skirt 2 with an internal annular cord 3, and is intended for a container 4, such as a bottle for a drink, made of plastic. He container 4 has a mouth 5 with an extreme opening surface flat 6 facing the cover 1 and (with reference to the drawing) a annular streak 7 under the mouth. The annular bead 3 fits that stria when lid 1 is in its closed state and retains the lid 1 securely over mouth 5 of container 4 by fast connection.

To ensure the longest life possible in container contents store 4, lid 1 has to be applied to the opening surface 6 mentioned above of a sealing mode completely impermeable to oxygen. To obtain this, there is arranged in the cover 1 an oxygen impermeable liner 8, in this case in the form of a thin sheet of aluminum 83 coated with a layer of heat-weldable plastic 81, 82, on both sides of the same. The liner 8 is placed in the lid 1 when molded by Inject the lid and, after mounting the lid 1 in the mouth 5 of the container 4 is welded by induction welding to the extreme opening surface 6 of the mouth 5.

In addition to sealing the lid 1 provided by induction welding, the lid 1 is also sealed to proof of fraud by means of a circumferential ring 9 that evidences that a fraud has been committed. As illustrated in the drawings, that hoop that evidences that a fraud has been committed is linked to the cover 1 below skirt 2 of cover 1 and, when mounting the lid 1 on the mouth 5 of the container 4, it is applied in a circumferential stretch mark (not shown) of the mouth 5. When open the lid 1, which is done as illustrated in Fig. 2, by pressing on the cover 1 to separate it from type 5, it it breaks the 9th ring that shows that a fraud has been committed, and it also breaks the weld joint between the liner 8 and the extreme opening surface 6 of the mouth 5, so that it is directly accessible the contents of the container 4.

In addition, the skirt 2 of the lid 1 has a radial projection 10 serving as a thumb grip at the end that mites towards the 9th ring that shows that committed fraud, to make it easier for the user to open the container 4. This projection 10 is preferably formed as an annular flange directed outward, but it can be designed, of course, in any suitable way.

The cover 1 described above is preferably manufactured by a manufacturing method that describes in the following with reference to a cover variant something simpler, without a hoop that evidences that a fraud, but for the sake of clarity the same numbers have been used of reference than for the preferred embodiment.

As seen in Fig. 3, the manufacturing is carried out by means of a mold 20 comprising a first mold part with a cavity and a second mold part 22 with a core, and is started by inserting a liner 8 , the mold 20 being open, as indicated by the arrow a , inside the cavity 23 of the first mold part 21, where it is applied to a wall 25 of the mold with a first flat side. The liner 8 is then held against the wall 25 of the mold by a negative pressure, which in this case has been illustrated by the arrow c , which is allowed to act through a central opening 27 in the wall of the mold. The mold 20 is then closed in the direction of the arrows b by means of the second mold part 22, whose core 24 is then inserted into the cavity 23 of the first mold part 21.

According to Fig. 4, the liner 8 is still held against the wall 25 of the mold in the closed mold 20, by the negative pressure c , and therefore does not yet make contact with the core 24 of the mold 20. This core 24 is preferably intersected by cooling channels 29, through which a refrigerant, indicated by arrows d , can be passed to regulate core temperature 24.

With reference to Fig. 5. a plastic 26 (the arrow e ) is then injected through the central opening 27 in the wall 25 of the mold, on the first flat side of the liner 8, which, as mentioned above , is coated with a first plastic layer 81. The injected plastic 26 flows on the flat side, presses the second opposite flat side, coated with the plastic layer 82, against the core 24, and completely fills a remaining cavity 28 between the mold parts 21, 22. Finally, the mold 2 'is opened and the finished lid 1 is removed with the liner 8 incorporated therein, after which the insertion step illustrated in Fig. 3.

Whoever is skilled in the art will find that the invention can be varied in a number of ways, within the scope of the claims. It is therefore conceivable to use different types of liners, such as a lining with more layers, or with layers other than those described above, apply joining methods other than induction welding, such as those of gluing and those of ultrasonic welding, and have covers on other types of containers other than plastic bottles or plastic cans, such as glass bottles or cans metallic

Claims (8)

1. A plastic lid for a container (4), whose lid (1), for oxygen impermeable sealing of the container (4), comprises an oxygen impermeable liner (8) to be attached to an opening end surface (6 ) of a mouth (5) in the container (4) and that for fixing to the mouth (5) has a circumferential skirt (2), which is arranged to surround that of the mouth (5) and which has an annular cord internal (3) adapted for quick connection with a corresponding annular groove (7) in the mouth (5), the liner (8) having an intermediate layer impermeable to oxygen (83), whose side facing the lid (1) is coated with a first plastic layer (81) arranged to be permanently attached to the lid (1) and whose face facing the container (4) is covered with a second plastic layer (82) arranged to be hermetically sealed, temporarily , to said opening end surface (6), and the liner (8) and the liner (8) and the cover (1) such that when the cover (1) is removed from the mouth (5) the liner (8) accompanies the cover (1), characterized in that said first plastic layer (81) is permanently joined by molding by injection to the lid (1) on the liner, to the plastic material of the lid (1), and because the skirt (2), at the end facing the container (4), has a radial projection (10), which serves as a gripping point for the thumb, and that when the container (4) is opened, it allows the lid (1) to bend out of said opening end surface (6) so that the seal is gradually broken Temporary seal between the second plastic layer (82) of the liner (8) and the extreme opening surface (6) of the mouth (5). 2. A plastic cover according to the claim 1, wherein said radial projection is a flange (10) extending along the entire circumference of the lid (one). 3. A plastic lid according to the claim 1 or 2, wherein the skirt (2) at the looking end towards the container (4) has a ring (9) that shows that committed a fraud, which is willing to cooperate with some corresponding retention means on the mouth (5) and so that is broken apart from the cover (1) when the cover (1) is removed from the mouth (5). 4. A plastic cover according to any one of claims 1-3, wherein the layer Intermediate (83) of the liner (8) is made of metallic material, of so that the liner 8 is weldable by induction welding to the extreme opening surface (6) of the container (4). 5. A plastic cover according to any one of claims 1-3, wherein the second plastic layer (82) of the liner (8) is a layer that is applicable to the extreme opening surface (6) of the container (4) by adhesive. 6. A plastic lid according to any one of claims 1-3, wherein second layer Plastic (82) of the liner (8) is a layer that is weldable to the extreme opening surface (6) of the container (4) by welding Ultrasonic 7. A method of manufacturing a lid (1) according to claim 1, by means of a mold (20), which comprises a first mold part (21) having a cavity (23) and a second part of mold (22) having a core (24), characterized by the steps of: insert a liner (8) while the mold is open (20) in the cavity (23) of the first mold part (21), where applied with a first flat side coated with a first layer of plastic (81) to a wall (25) of the mold, close the mold (20) by means of the second mold part (22), whose core (24) is then inserted into the cavity (23) of the first mold part (21), inject plastic (26) through at least one opening (27) in said wall (26) of the mold, on the first side plane of the liner (8), so that the plastic (26) flows over said flat side (81), press the second flat side of the liner (8) against said core (24), and fill a cavity (28) that is between the mold parts (21, 22), and open the mold (20) and remove the lid (1) finished with the lining (8) incorporated in it. A method according to claim 7, characterized in that the first flat side of the liner (8) is applied to said wall (25) of the mold by means of a negative pressure that is created in said at least one opening (27) in said wall ( 25) of the mold.